As is typical every time the sun decided to come out from behind the clouds today, I was busy. And by the time I was free, it had gone back into hiding. Finally caught up in the afternoon and this happened:

Celestron Nexstar 4SEBaader CaK filterCanon 450D all filters removed

Coronado PSTCanon 450D all filters removed

Cloud moved in just as I got a few shots off with the PST so I gave up at that point. I have aligned the images above as best I could using the sunspots.

I've got a weird ghosting effect only when using the CaK filter which I think is due to the camera but I'm not sure what the mechanism is yet. Multiple offset (same orientation) images with fading intensity. Like the Sony SLT mirror issue but with much greater spacing.

.Great captures. Now, if you got two images taken close together in time with no cloud I wonder what detail would be seen if you subtracted one from the other and then superimposed a false colour version of that difference image back on the H-alpha? I've no idea if it would work, if the background of the difference image could be sufficiently neutralised and if the resultant image would either reveal interesting stuff or would produce an even bigger Wow factor. Just a thought...